What is the recommended dose of amoxicillin (amoxicillin) for a pediatric patient weighing 70 pounds?

Amoxicillin Dosing for a 70-Pound Pediatric Patient

For a 70-pound (approximately 32 kg) pediatric patient, the recommended dose of amoxicillin is 45 mg/kg/day divided into two doses, which equals approximately 1440 mg per day or 720 mg twice daily. 1, 2

Dosing Considerations

Weight-Based Dosing

• For most common bacterial infections in children, amoxicillin should be dosed at 45 mg/kg/day in divided doses every 12 hours (twice daily) for mild to moderate infections 2
• For more severe infections, particularly respiratory tract infections, the dose can be increased to 90 mg/kg/day in divided doses every 12 hours 2
• The FDA-approved dosing for amoxicillin in children weighing less than 40 kg is 25-45 mg/kg/day divided every 12 hours for mild/moderate infections and 45 mg/kg/day divided every 12 hours for severe infections 1

Specific Infection Considerations

• For community-acquired pneumonia in children ≥5 years old, the recommended dose is 90 mg/kg/day in 2 doses (maximum 4 g/day) 2
• For streptococcal pharyngitis, the dose is 50-75 mg/kg/day in 2 doses 2
• For otitis media, the recommended dose is 40-45 mg/kg/day in 2 divided doses 2

Administration Guidelines

• Amoxicillin should be taken at the start of a meal to minimize gastrointestinal intolerance 1
• The oral suspension should be shaken well before using 1
• Treatment should generally be continued for a minimum of 48 to 72 hours beyond the time that the patient becomes asymptomatic 1
• For streptococcal infections, a minimum of 10 days of treatment is recommended to prevent acute rheumatic fever 1

Duration of Therapy

• Recent evidence suggests that shorter courses (5 days) of amoxicillin may be as effective as longer courses (10 days) for uncomplicated community-acquired pneumonia in children 3
• The WHO recommends a 5-day amoxicillin-based empiric treatment for community-acquired pneumonia 2, 3
• For otitis media, a 5-day course is typically sufficient 2

Common Pitfalls and Caveats

• Avoid underdosing, which can lead to treatment failure and promote antimicrobial resistance 2
• Be aware that amoxicillin dosing recommendations have increased over time due to increasing pneumococcal resistance 2
• For patients with severe renal impairment (GFR <30 mL/min), dose adjustment is necessary 1
• When treating suspected bacterial pneumonia in children, amoxicillin is preferred over amoxicillin-clavulanate unless there are specific concerns about beta-lactamase producing organisms 2, 4
• Amoxicillin-clavulanate has more gastrointestinal side effects than amoxicillin alone, so amoxicillin should be used when appropriate 4

Conversion from Pounds to Kilograms

• 70 pounds = approximately 31.8 kg (using the conversion factor 1 kg = 2.2 lbs)
• Therefore, for a 70-pound child:
  • Standard dose (45 mg/kg/day): 31.8 kg × 45 mg/kg/day = 1431 mg/day or approximately 720 mg twice daily 1
  • Higher dose (90 mg/kg/day): 31.8 kg × 90 mg/kg/day = 2862 mg/day or approximately 1430 mg twice daily 2

Remember that the specific dose should be selected based on the severity of infection and the suspected pathogen, with higher doses recommended for more severe infections or resistant organisms 2, 1.